You need to join their forum and register, but being in Spain and having no ITunes credit means that I've had to find a way of watching it online somehow. It's free and they have a next tab that leads you to the next episode and you can apparently stream them live, presumably while they are on bbc

If you can fill the unforgiving minute,With sixty seconds worth of distance run,Yours is the Earth and everything that's in it,And - which is more - you'll be a man my son.

Basically when humans spent too much time too close to the star they got burnt alive, and because of wibbly wobbly timey wimey stuff the burnt Clara and "salvagers" were trapped in a time loop on the tardis which would explain why they were attacking, because presumably they were trying to kill their earlier selves in a less horrific quicker manner.

If you can fill the unforgiving minute,With sixty seconds worth of distance run,Yours is the Earth and everything that's in it,And - which is more - you'll be a man my son.

I liked the interaction between Jenny & the doctor, particularly her response when he said "we need a plan!" And also his response after curing himself, particularly with what we can presume of her tastes!

If you can fill the unforgiving minute,With sixty seconds worth of distance run,Yours is the Earth and everything that's in it,And - which is more - you'll be a man my son.